The present invention relates to an optical disk apparatus, for recording or reproducing recording information through irradiating a light beam upon an information-recording medium, such as, being so-called a discoidal optical disk, and it relates to, in particular, an optical disk apparatus having a tilt adjustment mechanism for an optical pickup thereof, as well as, a sliding drive mechanism for an optical pickup having such the tilt adjustment mechanism therein.
In recent years, the optical disk apparatus, for recording or reproducing recording information through irradiating a light beam upon an information-recording medium, such as, being so-called a discoidal optical disk, accompanying with wide spreading of the information recording media, enabling recording/reproducing of a large amount of information, such as a CD-ROM and/or a DVD disk, etc., it is used widely, not only as an AV apparatus for recording/reproducing music and/or pictures, but also, as an apparatus of enabling to record/reproduce such the information media; i.e., as an exterior memory of a personal computer or the like.
On the other hand, in recent years, accompanying with small-sizing and low-pricing of such the personal computers and so on, but including the AV apparatus mentioned above therein, demand is made thereupon, strongly, also upon the optical disk apparatus, to be small in the sizes and low in the price thereof. However, in relation to the small-sizing of the optical disk apparatus, since the optical disks, being the information recording media to be used therein, such as, the CD-ROM and/or the DVD disk, etc., for example, are already determined in the sized thereof at the predetermined values, in accordance with a standard or the like thereof; therefore, it is strongly required that the apparatus itself comes to be thin in the type or size thereof, and accompanying with this, in most recent years, an optical disk apparatus appears on the market, which is so-called a super-thin type, being equal or less than 10 mm in the thickness size thereof.
By the way, for an optical pickup provided within such the optical disk apparatus, so as to satisfy such the strong demand made for thin-sizing mentioned above, it is necessary to be movable, freely and swiftly, in the radial direction of the optical disk inserted within the apparatus, but also within a very narrow space defined therein, and further, it is also necessary to conduct a focusing operation; i.e., focusing a laser beam irradiated upon the information recording surface of the disk.
Conventionally, in the structure for mounting the optical pickup on such the optical disk apparatus mentioned above, as is already known in the following Patent Document 1, for example, the optical pickup is hooked on a pair of rod-like shafts (i.e., a sliding main-shaft and a counter-shaft) at both ends thereof, and it is further attached with a lead screw provided in parallel with the sliding shaft, engaging on a portion thereof; thereby achieving the movement through rotating the lead screw by means of a disk motor, i.e., being made of a stepping motor or the like, for example.
And, in such the structure, conventionally, the adjustment mechanism for the tilt, i.e., an inclination angle of the optical pickup, is achieved by making adjustment only upon the inclination of the sliding main-shaft and the counter-shaft of the optical pickup. However, as a result of bringing the optical characteristics of the optical pickup to be optimal through the adjustment of that sliding main-shaft, there is caused an anxiety that a relative distance and/or an angle defined between the lead screw and the sliding main-shaft comes out from being constant, within an inside of the disk (i.e., a side near to the disk motor) and an outside thereof (i.e., a side far from the disk motor). In such the case, the lead screw may come out from the engagement with a rack therebetween; thus, there may be caused so-called jump-out from the screw. Further, since the strict restriction is made also upon the lead screw, in particular, in the depth of grooves (or, the teeth height of a screw), accompanying with the thin-sizing of the optical disk apparatus, then this also comes up to be a remarkable problem, in particular, in the optical disk apparatus, in particular, of such the super thin-type mentioned above.
However, with such the structure already known in that Patent Document 1, due to the tilt adjustment conducted when manufacturing the optical disk apparatus, the counter-shaft is attached on a substrate portion (i.e., a main chassis) through an adjustment mechanism portion thereof, while disposing a supporting portion of the sliding main-shaft and the stepping motor, on which the lead screw is attached, on a sub-substrate, thereby achieving a tilt adjustment through conducting an adjustment on that sub-substrate, in relation to the substrate portion (i.e., the main chassis).
Patent Document 1: Japanese Patent Laying-Open No. Hei 11-39661 (1999).